The invention relates to a process for controlling the speed of an internal combustion engine after starting, and until reaching an idling speed.
The starting process is terminated when the engine which has been disconnected from the starter continues to run under its own power and has reached a specific minimum speed. After this, the so-called after-start phase begins, during which the engine runs up to its predetermined idling speed. This idling speed is usually controlled in modern engine controls by means of an idling speed regulator.
During this after-start phase, there is still no stable operating state present. The speed usually increases very rapidly within approximately 0.3 to 1 second, from approximately 200 revolutions per minute after the start, to the temperature-dependent idling speed of approximately 600 revolutions per minute at approximately 20.degree. C. A slightly enriched mixture adjustment and early ignition angle values are usually provided here in order to ensure reliable running up.
However, the rapid increase in speed also causes the speed firstly to rise beyond the predetermined idling speed and only then to be subsequently controlled back to the idling speed by the idling speed regulator. As a result of this overshooting of the speed over the idling speed, increased exhaust gas emissions arise which are in any case already increased by the rich mixture setting and therefore by the not yet possible lambda control during the after-start phase.